Champion Radiators info on a 65 GTO.
 

Trying to get the 65 GTO mobile again to move to my shop since the storage space building is getting sold for condos. Original radiator leaking badly over the years so bought a Champion cheap aluminum. Friend with a 500" Mopar Charger had good luck with his.

First off mine is a 4bbl so has a passenger side top inlet and this is drivers side like the ri power and later motels-No big deal just a different thermostat housing and upper hose(I have a filter I bought also since the motor has some sludge in the passages).

Go to drop it in the brackets and it is too wide for the 3 core brackets. get some 4 core rubber and brackets from our host here and it is too narrow! So had to bend and rebend the 4 core lowers narrower and trim a new upper 3 core rubber isolator.

Bigger headache has been freeing up the rear drums locked up with a leak wheel cylinder!

Champion doesn't make a 65 GTO radiator. Just the 66-67 but refers to it as a 64-67. So which model did you choose? 2 row, 3 row or 4 row?

Fitment wise, pretty much all aluminum radiators made for GTO's are the 4 row tank style.

The more important issue is how it cools. I'll be the first to publicly admit that the 3 and 4 row may be fine for a number of different Pontiac motor combinations. There's plenty of owners using them successfully. However, there are also plenty of owners that spent the extra time and money because they have not gotten the job done. Pontiacs are particularly fussy when it comes to cooling especially rebuilt higher performance versions. If you combine that with the very noticeable 'home made race radiator' look and that's why I feel the need to make occasional comments about the validity of saving a few dollars.

Anyway, it would be helpful info to get the before and after temps at speed and in traffic as well as the performance aspects of your combination.

This one is definitely smaller than the 4 core tanks and as you said listed as a 64-65 but is a 66-67. I have a Rodney Red I picked up years ago(but was a taller A/C version so won't fit) that has slightly wider tanks that I assume are 4 core( roughly 3-3.100" wide). I just wanted a cheap option to fire the car up since the original was leaking at the tank seams badly and the original motor probably has a lot of rust scale that will break loose and possibly clog a good more expensive radiator. Recoring the original around here is almost as much a a new brass one this one was fairly cheap-but you get what you pay for and why it is not just a drop in. Just leting other folks know it is not a drop in.

I'll have to check how many rows. I had read "good" 1 or 1/25" tube 2 core aluminums cool as good as 4 core brass.

Double pass radiators cool more efficiently than standard crossflow as well.

We've got countless customers that have significant temp drops on even just the dual 1" tube models. With 1 1/4" tubes, it's not even close. Does everyone need that much cooling capacity? Probably not but if you are going to go thru the trouble of the installation and sometimes a brand new engine rebuild, why not play it safe and put something in there that you KNOW is going to get the job done. :)

btw, I have personal experience in this regard well before Cold Case even existed. I had a Rodney Red dual 1" unit in my 462 67 GTO. Despite RR being a well constructed well respected brand, it did not keep my GTO cool. I had to pull over if in traffic for any more than 20 minutes. I later dropped in a dual 1 1/4" aluminum unit and all else remained the same. Instead of overheating at 240-260 in 30-40 minutes, I have since run at 190-195 at the very most and that is when sitting in traffic for well over an hour.

Last Summer, we replaced that original big radiator that had dual 13" SPAL fans and a custom shroud (total cost of kit $1800) and replaced it with a $700 Cold Case kit. Cooling results are exactly identical to the $1800 kit. 190-195 all day long.

The champion I bought fit flawlessly in my 64 with the small radiator core support. I only upgraded to a cold case because they started offering the 66-67 style radiator with 1 1/4 tubes and I am gonna be making some serious power. My nephew adapted my champion to his mid 60s F100 and it’s cooking a beefed up 429 fine

Champion 2 rows and 2.680 wide tanks.

Another fit issue for the 65. The Champion is within 1/8" total height of the factory 3 core BUT since the tanks are totally smooth/rectangular unlike factory and others that have the corrugated look. So it sits 5.8" taller in regards to the core support and upper retainer bracket. Factory radiator tanks have those slots the supports fit into top and bottom dropping it down. The fan guard might be real tight against the hood.